Causes

Ringworm is caused by microscopic skin fungi that live on the outer layer of the skin. You can get ringworm from direct skin-to-skin contact with infected people or pets. It is also transmitted by sharing hats and personal hair grooming items, and through contact with locker room floors, shower stalls, seats, or clothing used by an infected person.

Risk Factors

Ringworm is more common in children 12 years of age or younger.

Factors that may increase your risk of developing ringworm include:

Contact with surfaces, clothing, or personal grooming items used by an infected person

Skin-to-skin contact with an infected person or pet

Spending time in nurseries, schools, daycare centers, or locker rooms

Symptoms

When ringworm appears on the skin, it makes circular, reddish patches with raised borders. Eventually, the patches grow larger, and the centers of the patches turn clear, giving a ring-like appearance.

Symptoms of ringworm on other parts of the body vary, for example:

Scalp,
tinea capitis
—begins with small bumps on the head that grow larger and form a circular pattern

Hair may become brittle and break, forming scaly, hairless patches.

Hands,
tinea manus—affects the palms and spaces between the fingers

Feet,
tinea pedis
or athlete's foot—may cause scaling between the toes, or thickening and scaling on the heels or soles

Nails,
tinea unguium
—causes fingernails and toenails to become yellow, thick, and crumbly

Ringworm symptoms on the body usually appear 4-10 days after exposure. Scalp symptoms will appear in 10-14 days.

Diagnosis

You will be asked about your symptoms and medical history. A skin examination will be done. Ringworm is often easily diagnosed by appearance. However, symptoms may be similar to other conditions. A sample of the affected area may be taken for testing.

Treatment

Treatment can be oral (taken by mouth) or topical (applied to skin):

Topical Treatment

This type of treatment is used for ringworm of the skin or body. It includes antifungal creams and powders. It usually takes at least 2 weeks for the ringworm to clear. After ringworm clears, treatment is usually continued for at least 2 more weeks.

For ringworm involving the body, hands, or feet, nonprescription treatment is highly effective.

Some medications are more effective than others.

Oral Treatment

This type of treatment is used for ringworm of the nails and scalp. Early treatment for scalp ringworm is important to prevent permanent hair loss. A culture or other test may be given to get an accurate diagnosis before beginning this kind of treatment. Prescription pills are given for:

Scalp ringworm: 4-8 weeks, and occasionally longer

Nail ringworm: 4-9 months, and occasionally longer

If you developed ringworm from your pet, your pet should be treated as well. Check with your pet's veterinarian for treatment procedures.

Prevention

The following steps may prevent ringworm:

Avoid contact with any infected person, animal, surface, or object.

Do not share personal hair grooming items, clothing, or shoes.

Wear sandals in locker room areas.

Avoid scratching during infection. This will prevent ringworm from spreading to other areas.

Wear clothing that minimizes sweating and moisture build-up.

Wear breathable shoes or sandals.

Keep moisture-prone areas of the body clean and dry.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.